Basin Electric partners with Mountrail-Williams to reduce transmission costs

Basin Electric is partnering with its member, Mountrail-Williams Electric Cooperative, headquartered in Williston, North Dakota, to develop transmission lines in three North Dakota locations.

“Basin Electric built a transmission line between Judson Substation (near Williston, North Dakota) and Tande Substation (near Tioga, North Dakota) in 2016. For three parts of that line, we worked with Mountrail-Williams to use double-circuit structures, one side of the structure carrying a 115-kV line and the other side carrying a 345-kV line. Near the new Springbrook substation, we also built a section that could support a future double circuit,” Bobby Nasset, supervisor of civil engineering, said. “Mountrail-Williams now needs a new 115-kV line from Springbrook to East Fork, so Basin Electric finished building that 6.5-mile segment in early November. It will be energized in early 2026 when the Springbrook substation is complete.”

When a line is constructed as double-circuit, two independent sets of conductors are used on the same tower. This allows for higher power transfer capacity, improved reliability, cost efficiency and better land use.

Mountrail-Williams also needs a new 115-kV transmission line from Crane Creek to Satterthwaite (north of New Town, North Dakota).

“Because we are building our new East Loop 345-kV transmission line (LOS-Crane Creek-Tande), our proposed line was very close to this new 115-kV need,” Nasset said. “Basin Electric and Mountrail-Williams developed an agreement to share costs and develop that segment together for 11.5 miles. That is currently under construction, with plans to energize in late 2026.

A third project is a 345-kV Pioneer (northwest of Williston, North Dakota) to Patent Gate (northwest of Watford City, ND), and Mountrail Williams is working on 115-kV Pioneer to Sanderson (west of Williston).

“Again, we share a common corridor for approximately 10 miles and have agreed to jointly develop that. We are in early permitting and routing stages, with energization scheduled for 2029,” Nasset said.

In each case, building the lines as double-circuits helps save on costs, but Nasset said there’s another big advantage.

“Working together reduces impacts and the need for two separate transmission lines and right-of-way, limiting the impacts to landowners and the environmental construction impacts,” Nasset said.